Support IP + STRING

Fixes #2205.

bin/varnishtest/tests/v00020.vtc

@@ -108,6 +108,10 @@ varnish v1 -vcl {
 		set req.http.foo = req.http.foo + "bar" ~ "bar";
 		set req.http.foo = req.http.foo + "bar" !~ "bar";
 
+		set req.http.foo = "foo" + req.ttl;
+
+		set req.http.foo = client.ip + ", " + server.ip;
+
 		set req.ttl = 1s;
 		set req.ttl *= 1.5;
 		set req.ttl = 1.5 s * 2.5;
@@ -141,9 +145,6 @@ varnish v1 -vcl {
 		else if (4) { }
 		else { }
 	}
-	sub vcl_backend_response {
-		set beresp.http.buzz = "ttl=" + beresp.ttl;
-	}
 }
 
 # XXX: not the most clear error message
@@ -238,6 +239,13 @@ varnish v1 -errvcl {DURATION + STRING not possible.} {
 	}
 }
 
+varnish v1 -errvcl {IP + IP not possible.} {
+	backend b { .host = "127.0.0.1"; }
+	sub vcl_recv {
+		set req.ttl = client.ip + server.ip;
+	}
+}
+
 varnish v1 -errvcl {Name of function, 'foo-bar', contains illegal character '-'} {
 	backend b { .host = "127.0.0.1"; }
 	sub foo-bar {

lib/libvcc/vcc_expr.c

@@ -1019,14 +1019,15 @@ static const struct adds {
 	{ '-', INT,		REAL,		REAL },
 
 	/* Error */
-	{ '+', TIME,		INT,		VOID },
-	{ '+', TIME,		REAL,		VOID },
-	{ '+', INT,		DURATION,	VOID },
-	{ '+', REAL,		DURATION,	VOID },
 	{ '+', DURATION,	INT,		VOID },
 	{ '+', DURATION,	REAL,		VOID },
 	{ '+', DURATION,	TIME,		VOID },
 	{ '+', DURATION,	STRING,		VOID },
+	{ '+', INT,		DURATION,	VOID },
+	{ '+', IP,		IP,		VOID },
+	{ '+', REAL,		DURATION,	VOID },
+	{ '+', TIME,		INT,		VOID },
+	{ '+', TIME,		REAL,		VOID },
 
 	{ EOI, VOID, VOID, VOID }
 };
@@ -1050,6 +1051,8 @@ vcc_expr_add(struct vcc *tl, struct expr **e, vcc_type_t fmt)
 		vcc_NextToken(tl);
 		if (f2 == TIME)
 			vcc_expr_mul(tl, &e2, DURATION);
+		else if (f2 == IP)
+			vcc_expr_mul(tl, &e2, STRING);
 		else
 			vcc_expr_mul(tl, &e2, f2);
 		ERRCHK(tl);